/*
 * ratelimit.c - Do something with rate limit.
 *
 * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com>
 *
 * 2008-05-01 rewrite the function and use a ratelimit_state data struct as
 * parameter. Now every user can use their own standalone ratelimit_state.
 *
 * This file is released under the GPLv2.
 */

#include <linux/ratelimit.h>
#include <linux/jiffies.h>
#include <linux/export.h>

/*
 * __ratelimit - rate limiting
 * @rs: ratelimit_state data
 * @func: name of calling function
 *
 * This enforces a rate limit: not more than @rs->burst callbacks
 * in every @rs->interval
 *
 * RETURNS:
 * 0 means callbacks will be suppressed.
 * 1 means go ahead and do it.
 */
int ___ratelimit(struct ratelimit_state *rs, const char *func)
{
	unsigned long flags;
	int ret;

	if (!rs->interval)
		return 1;

	/*
	 * If we contend on this state's lock then almost
	 * by definition we are too busy to print a message,
	 * in addition to the one that will be printed by
	 * the entity that is holding the lock already:
	 */
	if (!raw_spin_trylock_irqsave(&rs->lock, flags))
		return 0;

	if (!rs->begin)
		rs->begin = jiffies;

	if (time_is_before_jiffies(rs->begin + rs->interval)) {
		if (rs->missed) {
			if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE)) {
				pr_warn("%s: %d callbacks suppressed\n", func, rs->missed);
				rs->missed = 0;
			}
		}
		rs->begin   = jiffies;
		rs->printed = 0;
	}
	if (rs->burst && rs->burst > rs->printed) {
		rs->printed++;
		ret = 1;
	} else {
		rs->missed++;
		ret = 0;
	}
	raw_spin_unlock_irqrestore(&rs->lock, flags);

	return ret;
}
EXPORT_SYMBOL(___ratelimit);
it.cgi/linux/net-next.git/refs/?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>refs</a><a href='/cgit.cgi/linux/net-next.git/log/drivers/usb/storage/ene_ub6250.c'>log</a><a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/storage/ene_ub6250.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>tree</a><a class='active' href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/storage/ene_ub6250.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>commit</a><a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/storage/ene_ub6250.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/drivers/usb/storage/ene_ub6250.c'>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>drivers</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>usb</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/storage?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>storage</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/storage/ene_ub6250.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>ene_ub6250.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;</td><td class='right'>2017-01-30 19:27:10 -0500</td></tr>
<tr><th>committer</th><td>Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;</td><td class='right'>2017-01-31 09:13:49 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/storage/ene_ub6250.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>79c6f448c8b79c321e4a1f31f98194e4f6b6cae7</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/storage/ene_ub6250.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>370efda701f03cccf21e02bb1fdd3b852547d75c</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/storage/ene_ub6250.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>drivers/usb/storage/ene_ub6250.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/storage/ene_ub6250.c?id=0c744ea4f77d72b3dcebb7a8f2684633ec79be88'>0c744ea4f77d72b3dcebb7a8f2684633ec79be88</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/storage/ene_ub6250.c?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7&amp;id2=0c744ea4f77d72b3dcebb7a8f2684633ec79be88'>diff</a>)</td></tr></table>
<div class='commit-subject'>tracing: Fix hwlat kthread migration</div><div class='commit-msg'>The hwlat tracer creates a kernel thread at start of the tracer. It is
pinned to a single CPU and will move to the next CPU after each period of
running. If the user modifies the migration thread's affinity, it will not
change after that happens.

The original code created the thread at the first instance it was called,
but later was changed to destroy the thread after the tracer was finished,
and would not be created until the next instance of the tracer was
established. The code that initialized the affinity was only called on the
initial instantiation of the tracer. After that, it was not initialized, and
the previous affinity did not match the current newly created one, making
it appear that the user modified the thread's affinity when it did not, and
the thread failed to migrate again.

Cc: stable@vger.kernel.org
Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'>Diffstat</a> (limited to 'drivers/usb/storage/ene_ub6250.c')</div><table summary='diffstat' class='diffstat'>